Hey,

found an ad for an '87 250x. and it came with 2 spair 350x motors.

i know the 350x/250x swap is popular, but how much work is it to make it fit? will it just bolt on, or is there a lot more too it? (things are rarely that simple)

also, how much would a 350x and a 250x motor be worth? as in, i could sell off the spair motors to get back some extra $$. (i don't know the condition of any of the motors, but for discussion sake, let's say they're all in good shape).

and don't worry, i'm planning to read the archives about this. but the forum keeps going down. frustrating! lol

thanks,
bigmac

PS: i can't resist asking, how fast is a 350x/250x quad? would it be comparable to a 400EX?

 

There will always be nay sayers, but the ATC350X engine has more power potential than the 400EX engine.

TC Racing can get 65+ HP out of these engines easily......and that's without using the head and cylinder off of the FT500 motorcycle, which is a popular mod for these engines.

TC doesn't have a web-site that I know of, but they usaully have an ad in the mags with their phone number listed.

Powroll, makes the only engine conversion kit that I know of which doesn't require nothing the frame for clearance on the oil line bolt of the head. You can see a 250X with the 350X engine at powroll.com

The 350X has a 6 speed and no reverse and dual exhaust ports like the 400EX. The 350X engine is actually based off of the late 1970 XR500 engines.

The 250X has a 5 speed with reverse and a single exhaust port.

A 350X engine in good shape brings anywhere from $600.00 to $1000.00 on E-bay.

 

hey guys , knowsalot is very correct!! If you have a couple good donors I would go for it!! I myself have been looking back into the very same thing again. I have been trying to find out if the old XR500 topend will work on the 350X case with little modding ?? I currently have an 02 black / yellow 300EX that may get this treatment, along with lengthening and widening if I don't sell it first. The kits that powroll have is great , everything bolts right up , no prob. Oh yeah , bigmackloud if you get the engines and want to part with one or both let me know !!! I'm not too far from you

 

SCRamfusED,

There was a post from a few months ago from a guy who did the XR/FT500 top end conversion onto a 350X. He listed a few details that were required to do it right.

You might want to run a search for it because I can't recall the members name.

 

we made the conversion, it wasnt that hard you don't have run the valve cover motor mount, we did two of them. one was ours and one was my dad's friend's. ours was probably on par with stock raptors powerwise and it only had a high compression piston, 250x carb, and cobra exhaust. the other one has a tc racing motor so it will beat a raptor.if you do the conversion and have the 350x wiring use it(you have to use the 350x cdi box anyway), if you dont have it then you have to take the connector that has two wires, that plugs in to the cdi box on the 250x, and switch those two wires around [img]i/expressions/face-icon-small-cool.gif[/img]

 

Hey,

so if i can get this package deal for $1700 (or less if i haggle some), you think i should really go for it? i guess so. if i could even pull $500 per engine, that's $1000. so it'd be like getting a 250x for $700. but i'd really like to do the 350x swap. so i could just sell a spair 350x motor to pay for the conversion kit. i guess i'll give the guy a call and see what the details are.

thanks,
bigmac

 

the 350x swap is easy and very simpleif you private message me i can give you the entire run run on how to do it..it's very straight forward one mod and the motor is a direct fit.
i've done it several times and its well worth the time.
and yes tc racing has a small websit ei,it's new and doesn't have much but here it is.TC Racing enginesthey make some serious 350 x motor a buddy of mine down the road has a 490 /350x stroker motor 84 hp.